4-Oxo-4H-benzo{8 4.5{9 cyclohepta{8 1,2-b{9 thiophene derivatives

ABSTRACT

The invention concerns novel 4-oxo-4H-benzo(4,5)cycloheptal(1,2b)thiophene derivatives of the formula   WHEREIN R1 is hydrogen or lower alkyl, R2 IS HYDROGEN, FLUORINE, CHLORINE, BROMINE, LOWER ALKYL OR LOWER ALKOXY, R3 is hydrogen or lower alkyl, and A is ethylene or vinylene, useful as ANTIPHLOGISTIC AGENTS.

United States Patent Bastian PM Feb. 11, 1975 [541 4-0XO-4H-BENZO [57] ABSTR [4S]CYCLOHEPTA[IZ'BJTHIOPHENE The invention concerns novel 4-oxo-4H- [75 I Inventor: Jean-Michel Bastian. Therwil, Switzerland [73] Assignce: Sandoz Ltd. Bashe.

Switzerland [22] Filed: Apr. 2, 1973 [21] Appl. No.: 347,061

[30] Foreign Application Priority Data Apr. 7, 1972 Switzerland", 5l33/72 [52] U.S. Cl..... 260/332 .2 A, 260/3323 R, 424/275 [51] Int. CL; C07d 63/18, A6lk 27/00 [58] Field of Search... 260/332.2 A, 332.3 P, 329 F, 260/3325 [56] References Cited UNITED STATES PATENT I 3,464,983 9/1969 Jucker et al. 260/240 3,780,061 12/1973 Allais et al 260/3322 Primary ExaminerHenry R. Jiles Assistant ExaminerC. M. S. .laisle Attorney, Agent, or Firm-Gerald D. Sharkin; Richard E. Vila; Thomas O. McGovern benzo[4,5]cyclohepta[l,Z-blthiophene derivatives of the formula wherein R is hydrogen or lower alkyl, R is hydrogen, flyorine, chlorine, bromine, lower alkyl or lower alkoxy, .RziillyfiliQ fiIh flu rine; h orine b o lower vinylene, useful as antiphlogistic agents.

29 Claims, No Drawings 1 4-OX0-4H-BENZO [4,51CYCLOHEPTA[1,2-B]THIOPHENE DERIVATIVES IMPROVEMENTS IN OR RELATING TO ORGANIC COMPOUNDS The present invention relates to new 4-oxo-4H- benZo[4,5 ]cyclohepta[ l,2-b]thiophene derivatives.

The present invention provides compounds of formula l, I

wherein R, is hydrogen or lower alkyl,

R is hydrogen, fluorine, chlorine, bromine, lower alkyl or lower alkoxy,

R is hydrogen or lower alkyl, and

A is ethylene or vinylene.

Further, in accordance with the invention a compound of formula I may be obtained by a process comprising a. converting the CN group into the COOR group, wherein R is as defined above, in a compound of formula ll,

wherein R R and A are as defined above, with a compound of formula lll,

wherein R is lower alkyl, and

X is the acid radical of a reactive ester, to produce a compound of formula la,

1 I CH-COOR wherein R R and A are as defined above, and R is lower alkyl, or c. oxidizing a compound of formula W,

A S (IO-CH II I,

wherein R and A are as defined above, with a thallium (Ill) salt ofa strong, nonoxidizable acid in the presence of a strong acid and an alcohol of formula V,

wherein R is a primary lower alkyl group, to produce a compound of formula lc,

wherein R A and R are as defined above, or

d. hydrolyzing a compound of formula le,

1 I CH-'COOR wherein R R R and A are as defined above, to produce a compound of formula Id,

s cncoon wherein R R and A are as defined above.

R in the compounds of formula I preferably signifies hydrogen. The substituent R preferably denotes hydrogen or halogen of atomic number from 9 to 35.

When R is the latter it is especially chlorine. When R is a lower alkyl group, this may, for example, contain 1 to 4 carbon atoms and preferably denotes the methyl or ethyl group. When R is lower alkyl, this preferably contains 1 to 5 carbon atoms. The substituent R preferably is in the 6 or 7 position of the ring structure.

When R is lower alkoxy or alkyl, these groups preferably contain 1 to 3 carbon atoms and especially signify methoxy or methyl.

Processvariant (a) may be effected in known manner. For example, a compound of formula II may be allowed to react with water or a mixture of an alcohol of formula Va,

R -OH wherein R is as defined above, and water. The reaction may, for example, be effected in the presence of a strongly acidic or strongly basic catalyst, e.g., a strong mineral acid such as concentrated hydrochloric acid, 20 to 75 percent sulphuric acid or phosphoric acid, or a strong organic acid, e.g., an organic sulphonic acid, or, e.g., an alkali metal hydroxide solution, for example a 10 to 50 percent sodium or potassium hydroxide solution.

For the direct conversion of the CN group into the carboxyl group, a compound of formula ll may be heated in the presence of an acid catalyst preferably to a temperature from 60 to 120C, preferably to the reflux temperature of the reaction mixture, or in the presence of a strongly basic catalyst preferably to a temperature from 20 to 150C. The direct conversion reaction may be effected in water, alternatively in water and an inert water-miscible organic solvent, e.g., an alcohol such as ethanol, amyl alcohol or ethylene glycol, or an ether such as dioxane, or acetic acid.

For the conversion of the CN group into an ester group, the compounds of formula 11 may be reacted in an alcohol of formula Va containing an amount of water which is preferably equivalent to the amount of compound of formula II used. Any of the abovementioned solvents may be present and the reaction is preferably effected in the presence of an acid or basic catalyst for example as mentioned above, preferably at a temperature of about 50 to 100C. If desired, the compounds of formula ll may first be converted with the alcohol into the corresponding imino ethers which are subsequently hydrolyzed to the esters of formula I with a preferably equivalent amount of water.

Process variant (b) may, for example, be effected by reacting a compound of formula lb with a compound of formula 111, preferably a compound of formula lll wherein X is halogen or a mesyloxy or tosyloxy group, in an inert solvent, e.g., an aromatic hydrocarbon such as toluene or benzene, an ether such as dioxane or diethyl ether. The reaction is preferably effected in the presence of a basic condensation agent, e.g., sodium amide, potassium tert.butylate or sodium hydride, preferably at a temperature from about 25 to 100C.

Process variant (c) may, for example, be effected in the presence of an inert strong, non-oxidizable mineral acid, preferably perchloric acid. Suitable thallium (llI) salts are thallium (Ill) trinitrate or thallium (111) perchlorate, e.g., produced from the trinitrate in situ. Apart from an alcohol of formula V, e.g., methanol or ethanol, it is also possible to carry out the reaction in the presence of further inert organic, preferably watermiscible solvents, for example primary monoor polyvalent lower alkanols, cyclic ethers such as dioxane, or dimethyl formamide, or aromatic hydrocarbons such as benzene or toluene. The reaction temperature may be preferably from about to 50C. In accordance with a preferred method of the process, a solution of a compound of formula IV in an aromatic hydrocarbon or lower alcohol may, for example, be slowly added at room temperature to a solution containing a lto 1.5- fold molar amount of thallium (lll) trinitrate and a lto 10-fold molar amount of 70 percent aqueous perchloric acid dissolved in a lower alcohol such as methanol or ethanol, and conveniently up to a l5-fold molar amount of sodium perchlorate, and the mixture is al- 5 lowed to react at room temperature for about to 40 hours.

Process variant (d) may be effected in known manner for hydroylsis reactions. The reaction may, for example, be effected in the presence of a strongly acidic 10 or strongly basic catalyst, e.g., a strong mineral acid such as concentrated hydrochloric acid, 20 to 75 percent sulphuric acid or phosphoric acid, or a strong organic acid, e.g., an organic sulphonic acid, or, e.g., an alkali metal hydroxide solution, for example a 10 to 50 percent sodium or potassium hydroxide solution. The reaction may be effected in water, conveniently in the presence of an inert water-miscible organic solvent. Acid hydrolysis may, for example, be effected at a temperature from 60 to 120C, preferably. at the reflux temperature of the reaction mixture. Alkaline hydrolysis maybe effected at a temperature from about 20 to 150C.

The resulting compounds of formula 1 may be isolated from the reaction mixture and purified in known manner. Free acid forms of compounds of formula 1d may be converted into salt forms in conventional manner and vice versa.

The starting materials may, for example, be obtained as follows:

a. A compound of formula lla,

wherein R,', R and A are as defined above, may, for example, be obtained by reacting a compound of formula llb,

III) 1 CH-Cl wherein R R and A are as defined above, with a metal cyanide. It is preferred to use an alkali metal cyanide, e.g., sodium or potassium cyanide, or copper (I) cyanide. The reaction may, for example, be effected in an inert solvent such as water, acetone, at lower alcohol or dimethyl formamide, or a mixture of water and one of the organic solvents mentioned above, optionally with the addition ofa metal iodide such as sodium or potassium iodide. The reaction temperature may be from to 150C, preferably between 50 and 120C.

0. A compound of formula VI may, for example, be obtained by chloroalkylation of a compound of formula VII,

VII

wherein R and A are as defined above, for example by reacting a mixture of a compound of formula VII with an aldehyde of formula VIII,

R,-CHO

VIII

wherein R, is as defined above, or a polymer thereof in an acid solution, e.g. in aqueous hydrochloric acid or in acetic acid, while passing hydrogen chloride gas therethrough, or in a concentrated hydrochloric acid solution, conveniently at a temperature from about to +80C, preferably l0 and +50C.

d. A compound of formula IV may, for example, be obtained by acylating a compound of formula VII. The acylation may be effected in known manner, e.g., by reaction with acetic anhydride in the presence ofa catalyst, e.g., orthophosphoric acid, preferably at a temperature from about 50 to 150C, or with an acetyl halide in the presence of a Friedel-Crafts catalyst, e.g., aluminum trichloride, under the reaction conditions of a FriedeI-Crafts acylation.

Insofar as the production of the starting materials is not particularly described, these are known or may be produced in accordance with known processes, or in a manner analogous to the processes described herein or to known processes.

The compounds offormula I have not been described in the literature.

The compounds of formula I are useful because they possess pharmacological activity in animals. In particular, the compounds of formula I are useful as antiphlogistic agents, useful for the inhibition of exudation from inflammations or edemas, as indicated in standard tests, e.g., the Carrageen paw edema test in rats on p.o. administration of 1 to 20 mg/kg animal body weight, of the compounds, and in the granuloma cyst test in rats on p.o. administration of 3 to 50 mg/kg animal body weight, of the compounds.

For the above mentioned use the dosage will, of course, vary depending on the compound employed, mode of administration and therapy desired. However, in general, satisfactory results are obtained when administered at a daily dosage of from l mg to about 50 mg per kg animal body weight, conveniently given in divided doses 2 to 4 times a day in sustained release form. For the larger mammal, the total daily dosage is in the range from about 50 to about 300 mg, and dosage forms suitable for oral administration comprise from about 12 mg to about mg of the compounds admixed with a solid or liquid pharmaceutical carrier or diluent.

Specific examples of perorally administered daily dosages, at which satisfactory results are obtained, are:

i. 9,10-dihydro-4-oxo-4H-ben2o[4,5]cyclohepta[ l ,2- b]thiophene-2-acetic acid, from 1 to 50, e.g., 10 to 30, mg/kg animal body weigh/for animals in general, e.g., rats, and for the larger mammals from 50 to 300, e.g., 150 mg, and

ii. 4-oxo-4H-benzo[4,5]cyclohepta[ l ,2-b]thiophene- 2-acetic acid from I to 50, e.g., 3 to 30, mg/kg animal body weight, for animals in general, e.g., rats, and for the larger mammals from 50 to 300, e.g., I50 mg.

4-Oxo-4-H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene- 2-acetic acid has particularly interesting properties.

The compounds of formula I may be administered in free acid form. The compounds of formula Id may alternatively be administered in pharmaceutically acceptable salt form. Such salt forms exhibit the same order of activity as the free froms and are readily pre pared in conventional manner. Representative salt forms include alkali metal salt forms such as the sodium salt. A pharmaceutical composition may comprise a compound of formula I, in free acid form or in pharmaceutically acceptable salt form, in association with a pharmaceutical carrier or diluent. Such compositions may be prepared by conventional techniques to be in the form of, for example, capsules, tablets, suppositories, suspensions or solutions, for enternal or parenteral administration. Aside from the usual pharmaceutical diluents or carriers, e.g., water, alcohols, natural or hardened oils and waxes, these pharmaceutical compositions may contain suitable preserving, stabilizing, wetting solubilizing, sweetening, flavouring or colouring agents.

In one class of compounds of formula I, R is hydrogen, fluorine, bromine, chlorine or lower alkoxy.

In another class of compounds of formula I, A is vinylene.

In the following non-limitative Examples all temperatures are indicated in degrees Centigrade.

EXAMPLE 1 9, l 0-dihydro-4-oxo-4H-benzo[4,5 ]-cyclohepta[ 1,2 b]thiophene-2-acetic acid [process variant a) A mixture of 19.0 g of 9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ 1,2-b ]thiophene-Z-acetonitrile, 20 cc of glacial acetic acid, 20 cc of concentrated sulphuric acid and 20 cc of water is heated to the boil for 4 hours while stirring. After cooling, the reaction mixture is diluted with 250 cc of water, is extracted with methylene chloride and the resulting acid is extracted from the methylene chloride extracts with an 8 percent caustic soda solution. The pH of the aqueous basic solution is adjusted to 3 by the addition of 2 N hydrochloric acid at a temperature of 10 to 15, the resulting suspension is extracted with methylene chloride, the ex-' tracts are dried over magnesium sulphate and the solvent is removed by evaporation. The solid residue is re- M.P. of 138 to 140 (decomp.).

The 9,l-dihydro-4-oxo-4-H-benzo[4,5]- cyc1ohepta[l,2-b]thiophene-2-acetonitrile, used as starting material, may be produced as follows:

a. A mixture of 100 g of 9,10-dihydro-4-H- benzo[4,5]cyclohepta[1,2-b]thiophen-4-one in 700 cc of concentrated hydrochloric acid and 57 cc of a 40 percent formaldehyde solution is saturated with hydrogen chloride for 8 hours with vigorous stirring and cooling (10 to The mixture is allowed to stand at room temperature for 14 to 18 hours, is poured on 2.5 litres of ice water and extracted several times with chloroform. After drying over calcium chloride, the extracts are concentrated by evaporation and the resulting 2-chloromethyl-9, l 0-dihydro-4-oxo-4H- benzo[4,5]cyc1ohepta[l',2-b]thiophene is recrystallized from ether. M.P. 82 to 83.

b. 20 g of finely pulverized sodium cyanide and l g of sodium iodide are added to a solution of 100 g of 2- chloromethyl-9,l0-dihydro-4oxo-4l-lbenzo[4,5]cyclohepta[l,2-b]thiophene in 800 cc of N,N-dimethyl formamide. The mixture is stirred at 100 for 1% hours, is cooled to 20 and poured on 4 litres of water and 2 litres of ether. The mixture is stirred thoroughly for one hour and the ether solution is separated. The 9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ l ,2-b]thiophene-2-acetonitrile, obtained after evaporation of the solvent, crystallizes from ether. M.P. 92 to 94.

The following compounds of formula 1 may also be produced in a manner analogous to that described in Example 1 from the corresponding nitriles of formula 11: 6-chloro-9,10-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1 ,2-blthiophene-2-acetic acid,

calculated:

Analysis:

found:

6-fluoro-4oxo-4H-benzo[4,5]cyc1ohepta[1,2-b]thiophene-Z-acetic acid,

calculated: 11.1 S found: 11.2 S

Analysis: 62.5 C 9.1 H 62.3 C 9.0 H

5-methyl-4-oxo-4H-benzo[4,5]cyc1ohepta[1,2-b]thiophene-2-acetic acid,

calculated:

Analysis:

found:

EXAMPLE 2 .8 b. 4-oxo-4H-benzo[4,5 ]cyc1ohepta[ l ,2-blthiophene- Z-acetonitrile, produced in a manner analogous to that described in Example lb. M.P. 165 to 167 (benzene).

EXAMPLE 3 6-chloro-9,l0-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ l,2-b]thiophene-2-acetic acid 6-chloro-9,l0-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1,2-b]thiophene-Z-acetonitrile is reacted in a manner analogous to that described in Example 1. M.P. of the title compound l42143.

The starting material, 6-chloro-9,10-dihydro-4-oxo- 4H-benzo[4,5 ]cyc1ohepta[ 1 ,2-b]thiophene-2- acetonitrile, may be produced as follows:

a. A mixture of 50 g of 6-chloro-9,l0-dihydro-4H- benzo[4,5 ]cyc1ohepta[ l ,2-b]thiophen-4-one,6. 1 g of paraformaldehyde, 54 cc of glacial acetic acid, 40 cc of 85 percent phosphoric acid and 86 cc of concentrated hydrochloric acid isstirred at 80 for 5 hours, is poured on ice water and extracted with methylene chloride. The extracts are washed with water until neutral, dried over magnesium sulphate, and the solvent is removed by evaporation. 6-chloro-2-chloromethy1-9, l 0- dihydro-4H-benzo[4,5]cyc1ohepta[ l ,2-b]thiophen- 4-one is recrystallized from ether. M.P. 80 82.

b. A mixture of 21.5 g of 6-chloro-2-chloromethyl- 9,l0-dihydro-4l-1-benzo[4,5]cyc1ohepta[1,2- b]thiophen-4-one, 4.5 g of sodium cyanide and 0.5 g of sodium iodide in 170 cc of dimethyl formamide is heated to for 3 hours, is cooled, poured on water and extracted with benzene. After washing with water, drying over magnesium sulphate and removing the solvent by evaporation, 6-chloro-9,l0-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1,2-b]thiophene-2-acetonitrile is crystallized from hexane/ether. M.P. 128l30.

EXAMPLE 4 9,1(l-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1,2-blthiophene-2-acetic acid 9,lO-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ l,2-b]thiophene-2-acetonitrile is reacted in a manner analogous to that described in Example 1. M.P. of the title compound ll8l20.

The 9,1 O-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1 ,2-b]thiophene-Z-acetonitrile, used as starting material, may be produced as follows:

a. A solution of 18.5 g of 9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1 ,2-b]thiophene-2-acetonitrile in cc of benzene is added dropwise at room temperature to a suspension of 8.2 g of potassium-tert-butylate in 50 cc of absolute ether, and the mixture is stirred at room temperature for 2 hours. A solution of 1 1.5 g of methyl iodide in 50 cc of absolute ether is then added dropwise to the reaction mixture at room temperature, stirring is continued for one hour and the entire material is poured on 300 cc of ice water. The organic phase is separated, the aqueous solution is extracted with methylene chloride, the combined extracts are washed with water, dried over magnesium sulphate, and the solvent is removed by evaporation. The residue is used without further purification.

EXAMPLE 5 7-chloro-9, l0-dihydro-4-oxo-4H- benzo[4,5 ]cyc1ohepta[ 1,2-b]thiophene-2-acetic acid 7-ch1oro-9,l0-dihydro-4-oxo-4l-lbenzo[4,5 ]cyc1ohepta[ 1,2-b]thiophene-2-acetonitrile EXAMPLE 6 9,lO-dihydro-a-mthyl-4-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2-acetic ethyl ester acid A solution of 20.7 g of 9,l-dihydro-a-methyl-4-oxo-- 4H-benzo[4,5 ]cyclohepta[ l ,2-blthiophene-2- acetonitrile in l cc of absolute ethanol is saturated with hydrogen chloride at room temperature, is boiled at reflux for 24 hours and evaporated to dryness. the residue is taken up in 75 cc of ethanol and 2.2 cc of water, boiling is effected at reflux for 2 /2 hours and the mixture is again evaporated to dryness. The residue is taken up in benzene, washed with water, dried over sodium sulphate, and the solvent is removed by evaporation. The resulting title compound is purified by distillation. B.P. l85-l90 at 0.02 mm of Hg.

The following compounds of formula I may also be obtained in a manner analogous to that described in Example 6 by solvolysis of the corresponding acetonitriles of formula II: 6-fluoro-4-oxo-4H-benzo[4,5 ]cyclohepta[ 1 ,2-b]thiophene-Z-acetic acid ethyl ester,

Analysis: calculated: 6 6

H 10. found: H 9.

5-methyl-4-oxo-4H-ben2o[4,5 ]cyclohepta[ 1 ,2-b]thiophene-2-acetic acid ethyl ester,

calculated: found:

Analysis:

EXAMPLE 7 EXAMPLE 8 4-oxo-4H-benzo[ 4,5 ]cyclohepta[ l,2-b]thiophene2- acetic acid ethyl ester 4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2- acetonitrile is reacted as described in Example 6 to produce the title compound. B.P. 150-l60 at 0.01 mm of Hg.

' benzo[4,5 ]cyclohepta[ l,2-b]thiophene-2-acetic fphene-Z-acetonitrile EXAMPLE 9 6-chloro-9, l O-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ l,2-blthiophene-2-acetic ethyl ester The title compound is produced in accordance with Example 6, from 5.3 g of 6-chloro-9,l0-dihydro-4-oxo- 4H-benzo[4,5]cyclohepta[ l,2-b]thiophene-2- acetonitrile in cc of ethanol. B.P. 200-205 at 0.02 mm of Hg.

acid

EXAMPLE l0 6-chloro-9,l0-dihydro-a-methyl-4i-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-blthi0phene-2-acetic ethyl ester The title compound is produced in accordance with Example 6, from 5.2 g of 6-chloro-9,l0-dihydro-amethyl-4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thioin 8.0 cc of ethanol. B.P. l97-199 at 0.03 mm of Hg.

The 6-chloro-9,10-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-Z-acetonitrile, used as starting material, may be produced in a manner analogous to that described in Example 411, from 6- chloro-9, l0-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-Z-acetonitrile. M.P. l05l 12 (from benzene/hexane).

EXAMPLE 1 l 7-chlor0-9, l O-dihydro-4-oxo-4H- acid acid ethyl ester The title compound is produced in accordance with Example 6, from 10.0 g of 7-cli1loro-9,l0-dihydro-4- oxo-4H-benzo[4,5 ]cyclohepta[ l ,I2b]thiophene-2- acetonitrile in cc of ethanol. B.P. 2l5-218 at 0.04 mm of Hg.

EXAMPLE l2 4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2- acetic acid methyl ester [process variant c) 36.0 g of thallium trinitrate trihydrate, 32.0 g of sodium perchlorate, 16.0 cc of 70 percent perchloric acid and 260 cc of methanol are stirred at room temperature for l5 minutes. A solution of l2.0 g of 2-acetyl- 4H-benzo[4.5]cyclohepta[ l ,2-b]'thiophen-4-one in 230 cc of benzene is added dropwise to this solution, the mixture is stirred at room temperature for a further 40 hours, the precipitate is filtered off and the filtrate is poured on 2 liters of water. Extraction is effected with methylene chloride, the extracts are washed with water and with a common salt solution, are dried over sodium sulphate, and the solvent is removed by evaporation. The title compound is recrystallized from acetone/hexane. M.P. 72-74.

The 2-acetyl-4H-benzo[4,5 ]cyclohepta[ l ,2- b]thiophen-4-one, used as starting material, may be produced as follows:

a. 5 cc of 84 percent phosphoric acid are added dropwise to a solution of 10.0 g of 4H-benzo[4,5]cyclohepta[ l,2-b]thiophen-4-one in 50 cc of acetic anhydride. The reaction solution is stirred at ll0 for 1 hour, is poured on ice water and extracted with chloroform. The extracts are washed with water, dried over sodium sulphate and evaporated to dryness. The resulting 2- acetyl compound is crystallized from benzene. M.P. 156-159.

The following compounds of formula I may also be obtained in a manner analogous to that described in Example 12 by oxidation of the corresponding compounds of formula IV: 9,lO-dihydro-4-oxo-4H-benzo[4,5]cyclohepta[ 1,2- b]thiophene-2-acetic acid ethyl ester, B.P. 185195/0.04 mm Hg; 7-chloro-9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2-acetic acid ethyl ester, B.P. 215-218/0.04 mm Hg; 9,10-dihydro-6-methoxy-4-oxo-41-1- acid benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic methyl ester, analysis:

C 64.5 H,5.1" S 10.1% C 64.2 H 5.3 S 10.1 Z2

6-fluoro-4-oxo-4H-benzo[4,5 ]cyclohepta[1,2-b]thiophene-2-acetic acid methyl ester, analysis:

calculated .5 H 3.7 .7 H 3.9

S 0.6% found S 0.3

-methyl-4-oxo-4H-benzol4,5]cyclohepta[1,2-b]thiophene-2-acetic acid methyl ester, analysis:

calculated H 4.7 found H 4.5

EXAMPLE l3 EXAMPLE 14 9,1 O-dihydro-4-oxo-4H-benzo[4,5 ]cyclohepta[ 1 ,2- b]thiophene-2-acetic acid [process variant d) A mixture of 15.0 g of 9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ l,2-b]thiophene-2-acetic acid ethyl ester, 5.5 g of sodium hydroxide and 150 cc of nbutanol is stirred at the boil for 24 hours. After cooling, the mixture is poured on 1 liter of water, the aqueous solution is washed twice with benzene, and the pH of the solution is adjusted to 3 by the addition of 5 N hydrochloric acid. The precipitated acid is extracted with methylene chloride, the extracts are washed with water, dried over magnesium sulphate, and the solvent is removed by evaporation. The solid residue is recrystallized from benzene. The title compound has a MP. of l38-140 (decomp.).

ac id EXAMPLE l5 4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-blthiophene-2- acetic acid A suspension of 12 g of 4-oxo-4H- benzo[4,5 ]cyclohepta[ 1,2-b]thiophene-2-acetic acid ethyl ester in cc of water and cc of concentrated hydrochloric acid is boiled at reflux for 48 hours while stirring vigorously. After cooling, the mixture is extracted with methylene chloride and the extracts are washed with water. The methylene chloride solution is then extracted thrice with an 8 percent caustic soda solution, the basic aqueous solution is washed with ether and acidified at 10 to 15 by the addition of 5 N hydrochloric acid. The acid obtained as an oil is extracted with methylene chloride, theextracts are washed with water, dried over magnesium sulphate, concentrated by evaporation, and the residue is recrystallized from acetone. M.P. of the title compound 177-l79.

The following acids may also be obtained in a manner analogous to that described in Example 14 or 15 by hydrolysis of the corresponding esters in parentheses: 6-ch1oro-9, l O-dihydro-a-methyl-4-oxo-4H- benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic (from ethyl ester), analysis:

acid

calculated found C 60.0 H 7: C 59.9 H

6-fluoro-4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-Z-acetic acid (from ethyl ester), analysis:

calculated S 11 1 found S (from methyl ester), analysis:

acid

calculated C 67.2 H 4.9 S 1 2 70 found C 67.4 H 4.9 S

5-methyl-4-oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2-acetic acid (from methyl ester), analysis:

calculated 4.9 found 5 C67.1 H C67.4 H

EXAMPLE 16 6-chloro-9,10-dihydro-4-oxo-4H- benzo[4,5 ]cyclohepta[ 1 ,2-blthiophene-2-acetic acid A solution of 4.3 g of 6-chloro-9,l0-dihydro-4-oxo- 4H-benzo [4,5 ]cyclohepta[ l ,2-b]thiophen'e-2-acetic acid methyl ester and 1.5 g of potassium hydroxide in 70 cc of dioxane and 35 cc of water is stirred at room temperature for 20 hours, is then diluted with 250 cc of water and washed out with benzene. After acidifying with concentrated hydrochloric acid, the precipitated product is extracted with chloroform, the extracts are washed with water, dried over magnesium sulphate, and the solvent is removed by evaporation. The title compound is crystallized from the residue with benzene/hexane. M.P. 142143.

EXAMPLE l7 and the resulting title compound is recrystallized from acetone/benzene. M.P. ll8-120.

EXAMPLE l8 7-chloro-9,10-dihydro-4-oxo-4H- benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic acid This compound is produced in accordance with Ex ample 17, from 9.0 g of 7-chloro-9,10-dihydro-4-oxo- 4H-benzo[4,5 ]cyclohepta[ l,2-b]thiophene-2-acetic acid ethyl ester and 6.9 g of potassium hydroxide in 225 cc of methanol and 20 cc of water. MP. of the title compound 184-185 (from benzene/acetone).

EXAMPLE l9 9.lO-dihydro-a-methyl-4-oxo-4H- benzol4,5 ]cyclohepta[ 1 ,2-b]thiophene-2-acetic ethyl ester [process variant b) A solution of 21.5 g of 9,10-dihydro-4-oxo-4H- benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic acid ethyl ester in 75 cc of benzene is added dropwise at room temperature to a suspension of 8.2 g of potassium tert.butylate in 50 cc of absolute ether, and stirring of the mixture is continued for 2 hours at room temperature. A solution of 11.5 g of methyl iodide in 50 cc of absolute ether is added dropwise at room temperature to the reaction mixture, stirring is continued for 1 hour, the mixture is poured on 300 cc of ice water and the organic phase is separated. The organic solution is washed with water, concentrated and dried over sodium sulphate, and the resulting title compound is puritied by distillation.

B.P. 185190/0.02 mm Hg.

What is claimed is:

1. A compound of the formula acid Fix, S Cll-COOR R 1 3 1 T 2. The compound of claim 1, which is 9,10-dihydro- 4-oxo-4l-l-benzo[4,5 ]cyclohepta[ 11 ,2-b]thiophene-2 acetic acid.

3. The compound of claim 1, which is 4-oxo-4H benzo[4,5 ]cyclohepta[ 1,2-b]thiophene-2-acetic acid.

4. The compound of claim 1, which is 6-chloro-9,10- dihydro-4-oxo-4H-benzo[4,5]cyclohepta[1,2-b]thiophene-Z-acetic acid.

5. The compound of claim 1, which is 9,10-dihydroa-methyl-4-oxo-41-l-benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic acid.

6. The compound of claim 1, which is 7-chloro9,l0- dihydro-4-oxo-4l-l-benzo[4,5]cyclohepta[1,2-b]thiophene-Z-acetic acid.

.7. The compound of claim 1, which is 9,10-dihydroa-methyl-4-oxo-41-l-benzo[4,5]cyclohepta[1,2-b]thiophene-Z-acetic acid ethyl ester.

8. The compound of claim 1, which is 9,10-dihydroacetic acid ethyl ester.

9. The compound of claim 1, which is 4-oxo-4H- benzo[4,5]cyclohepta[1,2-b]thiophene-2-acetic acid ethyl ester.

10. The compound of claim 1., which is 6-chloro- 9,10-dihydro-4-oxo-4H-benzo[4,5 ]cyclohepta[ 1,2- ]thiophene-2-acetic acid ethyl ester.

11. The compound of claim 1., which is 6-chloro- 9,1 O-dihydro-a-methyl-4-oxo-4H- benzo[4,5 ]cyclohepta[ 1,2-b]thiophene-2-acetic ethyl ester.

12. The compound of claim 1., which is 7-chloro- 9,10-dihydro'4-oxo-4H-benzo[4,5]cyclohetpal1.2- b]thiophene-2-acetic acid ethyl ester.

13. The compound of claim 1, which is 4-oxo-4H- benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2-acetic acid methyl ester.

14. The compound of claim 1, which is 6chloro- 9,10-dihydro-4-oxo-4l-l-benzo[4,5]cyclohepta[1,2- b]thiophene-2-acetic acid methyl ester.

15. A compound of claim 1, wherein R is hydrogen or alkyl of 1 to 4 carbon atoms, R is hydrogen, fluorine, chlorine, bromine, alkyl of l to 3 carbon atoms or alkoxy of l to 3 carbon atoms, R is hydrogen or alkyl of 1 to 5 carbon atoms and A is ethylene or vinylene.

16. A compound of claim 15, wherein R is hydrogen, fluorine, chlorine or bromine and R is hydrogen.

17. A compound of claim 15, wherein R is alkyl of l to 5 carbon atoms.

18. A compound of claim 1 wherein R is hydrogen, fluorine, chlorine, bromine or lower alkoxy in the 6 or 7 position.

19. A compound of claim 18 wherein R, is lower alkyl having 1 to 4 carbon atoms.

20. A compound ofclaim 18 wherein R is hydrogen.

21. The compound of claim 1 which is 6-chloro-9, l0- dihydro-a-methyl-4'oxo4l-lbenzo[4,5 ]cyclohepta[ l ,2-b1thiophene-2-acetic acid.

22. The compound of claim 1 which is 6-fluoro-4- oxo-4l-l-benzo[4,5]cyclohepta[1,2-b]thiophene-2- acetic acid.

23. The compound of claim 1 which is 5-methyl-4- oxo-4H-benzo[4,5]cyclohepta[1,2-b]thiophene-2- acetic acid.

24. The compound of claim 1, which is 6-fluoro-4- oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2- acetic acid ethyl ester.

acid

15 25. The compound of claim 1 which is 5-methyl-4- acetic acid methyl ester.

28. The compound of claim 1 which is 5-methyl-4- oxo-4H-benzo[4,5 ]cyclohepta[ l ,2-b]thiophene-2- acetic acid methyl ester.

29. The compound of claim 1 which is 9,l0-dihydro- 6-methoxy-4-oxo-4H-benzo[4,5]cyclohepta[ 1,2-

b]thiophene-2-acetic acid. 

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1, which is 9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 3. The compound of claim 1, which is 4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 4. The compound of claim 1, which is 6-chloro-9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 5. The compound of claim 1, which is 9,10-dihydro- Alpha -methyl-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 6. The compound of claim 1, which is 7-chloro-9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 7. The compound of claim 1, which is 9,10-dihydro- Alpha -methyl-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 8. The compound of claim 1, which is 9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 9. The compound of claim 1, which is 4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 10. The compound of claim 1, which is 6-chloro-9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-)thiophene-2-acetic acid ethyl ester.
 11. The compound of claim 1, which is 6-chloro-9,10-dihydro-Alpha -methyl-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 12. The compound of claim 1, which is 7-chloro-9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohetpa(1,2-b)thiophene-2-acetic acid ethyl ester.
 13. The compound of claim 1, which is 4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid methyl ester.
 14. The compound of claim 1, which is 6-chloro-9,10-dihydro-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid methyl ester.
 15. A compound of claim 1, wherein R1 is hydrogen or alkyl of 1 to 4 carbon atoms, R2 is hydrogen, fluorine, chlorine, bromine, alkyl of 1 to 3 carbon atoms or alkoxy of 1 to 3 carbon atoms, R3 is hydrogen or alkyl of 1 to 5 carbon atoms and A is ethylene or vinylene.
 16. A compound of claim 15, wherein R2 is hydrogen, fluorine, chlorine or bromine and R3 is hydrogen.
 17. A compound of claim 15, wherein R3 is alkyl of 1 to 5 carbon atoms.
 18. A compound of claim 1 wherein R2 is hydrogen, fluorine, chlorine, bromine or lower alkoxy in the 6 or 7 position.
 19. A compound of claim 18 wherein R1 is lower alkyl having 1 to 4 carbon atoms.
 20. A compound of claim 18 wherein R2 is hydrogen.
 21. The compound of claim 1 which is 6-chloro-9,10-dihydro-Alpha -methyl-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 22. The compound of claim 1 which is 6-fluoro-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 23. The compound of claim 1 which is 5-methyl-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid.
 24. The compound of claim 1, which is 6-fluoro-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 25. The compound of claim 1 which is 5-methyl-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid ethyl ester.
 26. The compound of claim 1 which is 9,10-dihydro-6-methoxy-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2 -acetic acid methyl ester.
 27. The compound of claim 1 which is 6-fluoro-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid methyl ester.
 28. The compound of claim 1 which is 5-methyl-4-oxo-4H-benzo(4, 5)cyclohepta(1,2-b)thiophene-2-acetic acid methyl ester.
 29. The compound of claim 1 which is 9,10-dihydro-6-methoxy-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)thiophene-2 -acetic acid. 